Flip-flop alarm system with lamp test circuit



W. JACKSON Oct. 3, 1967 -FLOP ALARM SYSTEM WITH LAMP TEST CIRCUIT FLIPFiled June 18, 1965 3 Sheets-$heet 1 INVENTOR WILBUR JACKSON ATTORNEYOct.'3, 1967 w. JACKSON 3,345,628

FLIP-FLOP ALARM SYSTEM WITH LAMP TEST CIRCUIT Filed June 18, 1965 3Sheets-Sheet 2 v INVENTOR WILBUR JACKSON N QE S mm iv ATTORNEY w.JACKSON 3,345,628

FLIP-FLOP ALARM SYSTEM WITH LAMP TEST CIRCUIT Oct. 3, 1967 3Sheets-Sheet 5 Filed June 18, 1965 R O mm E m mm m R g m w & @mm ma: EN:N9 E Emma 1| IL. a? fl m N2 m 5 a +5? NN 8 mm N k N mm 3 mvu 8 MW 0? 8mQommv 3 m p 3v Q NI 1 own a w i w- ATTORNEY United States Patent OfiiceABSTRACT OF THE DISCLQSURE This device is for monitoring conditions at aremote station which transmits an identifying tone signal followed byone of two subsequent tone signals characteristic of conditions to bemonitored. A first resonant relay responds to the identifying tonesignal, and one or the other of two other resonant relays responds toone or the other of the subsequent tone signals. Ordinarily, one of thesubsequent tone signals characterizes a normal condition at the remotestation and the other subsequent tone signals characterizes an abnormalcondition. An alarm circuit remains unresponsive to relay response tonormal condition tone signals, but is actuated by relay response to anabnormal condition tone signal. Once actuated, the alarm circuitrequires a forced reset to de-activate it.

This invention relates to an alarm system responsive to encoded signalsof predetermined sequence characteristics and, more particularly, to aflip-flop relay and alarm system requiring manual reset in order to shutoff the alarm.

The primary object of this invention is to provide an alarm system formonitoring of operating conditions at one of a plurality of remotestations so as to sound an alarm upon deviation of a condition at theremote station from a predetermined norm. By way of example, let it beassumed that the remote station incorporates a power-consuming device,and it is desired to know, at a central station, the on and offconditions of the remote stations power supply. Let it further beassumed that a multi-tone transmitter at the remote station periodicallytransmits first an identifying tone, i.e., a be of predeterminedfrequency, and then either a ha of lower tone representing a power oncondition, or a ho of still lower tone representing a power offcondition. The object of this invention is to provide, for use as acentral station, an alarm system which will turn on an indicator lampand sound an audible signal, hereinafter termed a bell, upon deviationof the received tones from a first tone sequence to a second tonesequence and which, in order for the operator to shut off the bell,requires him to preset and precondition the control circuit so that itbecomes responsive only to the second tone sequence.

Another object of the invention is to provide a bell relay and pluralsignal lamp test circuit by means of which all the signal lamps and thebell relay may be simultaneously tested without appreciable dimming ofthe lamps. Assuming, for example, that the supply circuit is 12 volts,each signal lamp and an associated resistor thereacross has a totalvoltage drop of 6 volts, and assuming further that a bell alarm relayWinding and an associated resistor thereacross has a total voltage dropof 6 volts, and the lamps are in series parallel with the bell relay. Solong as only one lamp is being tested, sufficient current will normallyflow through the bell relay Winding so that its illumination will benormal. However, if both lamps are to be tested simultaneously with thebell relay, insuificient current would normally flow through the bellrelay to provide for pull-in of the bell relay and full illumination ofboth lamps, and the operator could not judge whether there is any faultand, if so, where. The object now is to provide, in such a 3,345,628Patented Oct. 3, 1967 circuit, a zener diode in parallel with the hellrelay, and hence in series with both lamp circuits, the zener diodehaving a knee at about 6 volts. Thus, if only one lamp is tested, thecurrent flowing through the relay winding and its associated resistor issufficient for pull-in of the relay and illumination of the lamp; and ifboth lamps are tested simultaneously, the needed additional current willbypass the relay winding via the zener diode, and both lamps and therelay winding will be fully energized.

These and other objects will be apparent from the followingspecification and drawings, in which:

FIG. 1 is a circuit diagram of the alarm circuit in first conditionwherein it will be assumed that a power on code tone sequence has justbeen received and the operator has not yet reversed the reset switch;

FIG. 2 shows the circuit in the same condition as FIG. 1 with theexception that the operator has reversed the reset switch, therebyextinguishing the hell, it being assumed that the power-011 tonesequence is continuing; and,

FIG. 3 shows the circuit in the condition resultant when a power-01ftone sequence is received.

Referring now to the drawings, which are similar diagrams heavy-lined toshow the same circuit in three typical conditions, it will be assumedthat there are fed into a signal input terminals 2 and 4 sequencesof-tone code signals denoting the condition of a device, presumably at aremote station, to be monitored. If, in this example, the on-offcondition of a power supply at the remote station is being monitored,the remote transmitter would transmit a tone code signal be-ha or be-b0.The frequency of the he would identify the particular device, i.e., thepower supply, from which the report originates. The ba freqency denotesan on condition, and the be denotes an olf condition.

Signal input terminals 2 and 4 are respectively connected to conductors6 and 8, across which are respectively connected, in series, thewindings and potentiometers 10a and 12a, 10b and 12b, and 19a and 11k ofthree resonant relays A, B and C. The reed '14 of a resonant relay A istuned to resonate only in response to the particular be tone signalidentifying the monitored device, reed 14b of resonant relay B beingtuned to resonate only in response to the ba tone signal identifying onecondition (in this example on) of the monitored device, and reed ofresonant relay C being tuned to resonate only in response to the b0 tonesignal identifying another condition (such as oft) of the monitoreddevice.

The contact 16a of resonant relay A is connected, on the one hand, viaconductor 18 and capacitor 50a to the positive bus 22 of a 12 volt powersupply circuit, whereas the reed 14a is connected to the negative, orground, bus 24 of the power supply circuit. Hence, when reed 14avibrates against contact 16a, capacitor 50a charges. A potentiometer 20is connected across capacitor 50a in order to bleed oil. the chargebetween the bes which are periodically received at regular intervals.The negative side of capacitor 50a is also respectively connected viaconductors 26, 26 to the contacts 28 and 30 of two four-poledouble-throw relays 32 and 34. The reed 14b of resonant relay B isconnected by a lead 36 to the arm 38 which sometimes cooperates withcontact 28' of relay 32, and the reed 140 of resonant relay C isconnected via lead 40 to arm 42 which sometimes cooperates with contact30 or relay 34.

A lead 44b connects the base 46b of a transistor Tb to the contact 16bof resonant relay, and a circuit 47!) which includes resistor 48bconnects base 46b to ground, normally biasing the transistor to cut-oil.A similar circuit 470 including resistor 48b also normally biasestransistor Tc to cut-off. However, connected across resistors 48b and48c are capacitors 50b and 500, respectively, which when charged, biasthe bases of their associated transistors to cause emitter-collectorconduction. The collectors of transistors Tb and Tc are respectivelyconnected via leads 54b and 540 to negative bus 24, and their emitters56b and 560 are connected via lead 58b and winding 60b of relay 32 orlead 58 c and winding 60c of relay 34 to positive bus 22. Thus, iftransistor Tb conducts, relay 32 pulls in as shown in FIG. 1, and if Tcconducts, then relay 34 pulls in as shown in FIG. 3.

A holding circuit for relay 32 is established in the out condition ofrelay 34 (FIGS. 1 and 2) from ground bus 24 via lead 62 arm 64 andcontact 66 of relay 34, via conductor 68 to connection 70 to lead 58band thence via winding 60b of relay 32 back to the positive bus 22.Likewise, a holding circuit for relay 34 is established in the outcondition of relay 32 (FIG. 3) from ground bus 24 by lead 72, arm 74 andcontact 76 of relay 32, conductor 78 and connection 80 to lead 580 andthence via winding 60c of relay 34 back to positive bus 22. Obviously,only one relay can be held on at any given time.

Refer-ring to the circuit in the FIG. 3 condition, let it be assumedthat there has previously been a power oi? signal which has created theFIG. 3 condition, the reversing switch 90 detailed below has been movedby the operator to the FIG. 1 condition, and then a be-ba (power on)signal has been receive-d. The be tone signal causes reed 14a ofresonant relay A to vibrate, thereby engaging contact 16a so as toperiodically connect the negative side of capacitor 50a to ground bus 24and charge capacitor 50a upon receipt of the ba tone, reed 14b ofresonant relay 14b vibrates against contact 16b of resonant relay B,thereby placing the negative bias of capacitor 50 on base 46 oftransistor Tb and also charging up capacitor 50b. Transistor Tb isbiased on, and the on biasing charge on capacitor 50b remains longenough for relay 32 to pull in. Relay 34 then being out, the holdingcircuit for relay 32 is established.

An indicator lamp and alarm circuit denoting the receipt of theexemplified power on tone sequence is established (FIG. 1) from groundbus 24, lead 72, arm 74 and contact 82 of relay 32 and thence viaconductor 84, 6 volt signal lamp 86 arm 88 of reversing switch arm 90,contact 92 branch 94 and conductor 96 through the winding 98 of a bellrelay 100, and thence via lead 102 back to positive bus 22. K resistors104 and 106 are connected across lamp 86 and relay winding 106. Alsoparalleling relay winding 98 and resistor 106 is a zener diode 108having a knee at about 6 volts, for purposes described hereinafter.Thus, when the be-ba signal actuates the circuit to the FIG. 1condition, indicator lamp 86 goes on, the circuit 110 for bell 112 isclosed, and the operator must flip reversing switch 90 to its FIG. 2condition in order to silence bell 100. However, in so doing, an

energizing circuit for lamp 86 is maintained via arm 88 of reversingswitch 90, contact 114, resisttor 116 and lead 118 back to positive bus22.

FIG. 2 illustrates the condition in the circuit after th operator hassilenced bell 112. Lamp 86 stays on so long as a be-ba tone signalsequence, or no signal at all, prevails. However, upon receipt of abe-b0 tone signal sequence, reed 14a of resonant relay A resonates withthe be tone signal, capacitor 50a charges, reed 14c of resonant relay Cresonates with the b0 tone signal, thereby charging capacitor 500 andimposing the negative bias on base 460 of transistor Tb. When transistorTb goes on, relay 34 pulls in, thereby breaking the holding circuit forrelay 32 and the latter then establishes the holding circuit for relay34 and breaks the energizing circuit for signal lamp 86.

When relay 34 pulls in a signal lamp and bell relay energizing circuitis established from ground bus 24 through lead 62, arm 64, contact 120,conductor 122, lamp 124, lead 126, arm 128 and contact 13 of reversingswitch 90, conductor 94 and back to positive bus 22 via bell relaywinding 98 and its parallel resistor 106 and conductor 102. Bell 112must be silenced by flipping reversing switch back to its FIG. 1position, whereupon an alternate energizing circuit for lamp 124 ismaintained via arm 128 and contact 138 of reversing switch and back topositive bus 22 via resistor 136 and leads 134, 118. Lamp 132, whichalso is rated at 6 volts, also has a 10K resistor across it to maintaincirciut continuity in event its filament burns out.

Reverting now to the FIG. 2 condition, let it be assumed that theoperator desires to test both lamps 86 and 124 and bell relaysimultaneously. Lamp 86 is already energized via the held arm 74 andcontact 82 of relay 32. By closing test switch 140, an additionalenergizing circuit for both bell relay 100 and lamp 124 is establishedfrom positive bus 22 via conductor 102, bell relay winding 98 and itsparallel resistor 106, conductor 96, contact 130 and arm 128 ofreversing switch 90, lead 126, through lamp 124 and its parallelresistor 132 and thence via conductor 142 and rectifier 144 throughswitch to ground. If the conditions of relays 32, 34 are reversingswitch 90 were reversed and from the FIG. 2 condition lamp 124 were on,the test circuit for lamp 86 would run from branch 94 through contact 94and arm 88 of reversing switch 90, through lamp 86 and its parallelresistor 104 and thence through conductor 146, rectifier 148 and testswitch 140 to ground. Assuming a voltage drop of approximately 6 voltsacross both lamps and their associated resistors, which would then be inseries with bell relay winding 98 and its resistor 106, insufficientcurrent would normally blow through winding 98 and resistor for fullillumination of both lamps and for pullin of relay 100, and the voltagedrop across relay winding 98 and its resistor would normally rise toabout 9 volts. However, when the voltage drop across winding 98 andresistor 106 exceeds 6 volts, then zener diode 108 conducts andestablishes a partial shunt around winding 98 and resistor 106, therebysupplying ample current at full 6 volts to lamps 86 and 124.

The invention is not limited to the details of the circuit disclosed anddescribed hereinbefore, but is intended to cover all substitutions,modifications and equivalents within the scope of the following claims.

I claim:

1. A multi-tone decoding and signalling device comprising, a tone signalinput circuit, first, second and third resonant relays each having acontrol winding connected across said tone signal input circuit and eachhaving power input and output connections and each resonant relay beingresponsive only to first, second and third tone signals of respectivelydifi'erent frequencies, a power supply circuit including two conductorsof opposite polarity, a first capacitor and charging circuit thereforconnected to said power supply circuit and the power output connectionof the first resonant relay for charging said first capacitor uponenergization of the control winding of the first resonant relay by afirst tone signal, first and second switching transistors each havingcontrol elements respectively connected to the power output connectionsof said second and third resonant relays, first and second relay meansincluding control windings respectively associated with said first andsecond transistors and having certain contact and armature pairs whichare normally closed when their windings are de-energized and certainother contact pairs which are closed when their windings are energized,a pair of power circuits across said power input conductors and runningrespectively through controlled elements of said first and secondtransistors and the control windings of the first and second relay meansrespectively associated therewith, said first and second relay meanseach including a first normally open contact and armature pair forestablishing a transistor on-switching circuit from said first capacitorto the power input connections of said second and third resonant relaysrespectively when said first and second relay windings are de-energizedand for breaking said transistor on-switching circuit when said relaywindings are energized, means for normally biasing the control elementsof said transistors to oif switched states, a holding circuit for eachrelay means winding established through a normally closed contact andarmature pair of the other relay means and each being opened uponenergization of the other relay means winding, whereby the holdingcircuits of said relay means operate in flip-flop mode, first and secondelectrically energizable signal devices, and first and second energizingcircuits respectively for the first and second signal devices runningfrom one power conductor through normally open contact and armaturepairs on the first and second relay means to the other power conductor.

2. The combination claimed in claim 1, the means for normally biasingthe control elements of said transistor to off switched states eachincluding a circuit running from one of said power conductors to thecontrol element of the respective transistor to which the outputconnection of a resonant relay is connected, a series resistor, in eachof the last-named circuits, and a capacitor connected across theresistor.

3. A multi-tone decoding and signalling device comprising, a tone signalinput circuit, first, second and third resonant relays each having acontrol winding connected across said tone signal input circuit and eachhaving power input and output connections and each resonant relay beingresponsive only to first, second and third tone signals of respectivelydilferent frequencies, a power supply circuit including two conductorsof opposite polarity, a first capacitor and charging circuit thereforconnected to said power supply circuit and the power output connectionof the first resonant relay for charging said first capacitor uponenergization of the control winding of the first resonant relay by afirst tone signal, first and second switching transistors each havingcontrol elements respectively connected to the power output connectionsof said second and third resonant relays, first and second relay meansincluding control windings respectively associated with said first andsecond transistors and having certain contact and armature pairs whichare normally closed when their windings are de-energized and certainother contact pairs which are closed when their windings are energized,a pair of power circuits across said power input conductors and runningrespectively through controlled elements of said first and secondtransistors and the control windings of the first and second relay meansrespectively associated therewith, said first and second relay meanseach including a first normally open contact and armature pair forestablishing a transistor on-switching circuit from said first capacitorto the power input connections of said second and third resonant relaysrespectively when said first and second relay windings are de-energizedand for breaking said transistor on-switching circuit when said relaywindings are energized, means for normally biasing the control elementsof said transistors to off switched states, a holding circuit for eachrelay means winding established through a normally closed contact andarmature pair of the other relay means and each being opened uponenergization of the other relay means winding, whereby the holdingcircuits of said relay means operate in flip-flop mode, first and secondelectrically energizable visual indicator devices, an electricallyenergizable audible alarm device, ganged first and second reversingswitches each having an armature and first and second contacts againstwhich said armatures are simultaneously alternately closable, anenergizing circuit for said audible alarm device running from one powerconductor to the first contact of the first reversing switch and thesecond contact of the second reversing switch, an energizing circuit forfirst visual indicator device running from the other power conductorthrough a normally open of the first relay means to the circuit for thesecond vis 4. The combination claimed in claim 3, and alternate aidfirst and second visual indicator devices running from the secondcontact of the first refrom the first contact of the second reversingswitch to said other conductor of the power supply, whereby one or theother of said visual indicator devices remains energized regardless ofwhether the energizing circuit for the audible alarm is closed.

5. The combination claimed in claim 3, said audible alarm and visualindicator energizing circuits all including power consuming devices,means including said reversing sw tches for placing said visualindicator energizing circults in parallel with one another and in serieswith the energizing circuit of said audible alarm device, said powersupply circuit being for direct current of fixed voltage and a zenerdiode connected across the power-consuming device in the energizingcircuit of the audible alarm device, whereby to bypass current to thepower consuming device in the visual indicator device circuits when thevoltage drop across the power consuming device in the audible alarmcircuit exceeds a predetermined level.

References Cited UNITED STATES PATENTS NEIL C. READ, Primary Examiner,I. LEVIN, A. J. KASPER, Assistant Examiners.

1. A MULTI-TONE DECODING AND SIGNALLING DEVICE COMPRISING, A TONE SIGNALINPUT CIRCUIT, FIRST, SECOND AND THIRD RESONANT RELAYS EACH HAVING ACONTROL WINDING CONNECTED ACROSS SAID TONE SIGNAL INPUT CIRCUIT AND EACHHAVING POWER INPUT AND OUTPUT CONNECTIONS AND EACH RESONANT RELAY BEINGRESPONSIVE ONLY TO FIRST, SECOND AND THIRD TONE SIGNALS OR RESPECTIVELYDIFFERENT FREQUENCIES, A POWER SUPPLY CIRCUIT INCLUDING TWO CONDUCTORSOF OPPOSITE POLARITY, A FIRST CAPACITOR AND CHARGING CIRCUIT THEREFORCONNECTED TO SAID POWER SUPPLY CIRCUIT AND THE POWER OUTPUT CONNECTIONOF THE FIRST RESONANT RELAY FOR CHARGING SAID FIRST CAPACITOR UPONENERGIZATION OF THE CONTROL WINDING OF THE FIRST RESONANT RELAY BY AFIRST TONE SIGNAL, FIRST AND SECOND SWITCHING TRANSISTORS EACH HAVINGCONTROL ELEMENTS RESPECTIVELY CONNECTED TO THE POWER OUTPUT CONNECTIONSOF SAID SECOND AND THIRD RESONANT RELAYS, FIRST AND SECOND RELAY MEANSINCLUDING CONTROL WINDINGS RESPECTIVELY ASSOCIATED WITH SAID FIRST ANDSECOND TRANSISTORS AND HAVING CERTAIN CONTACT AND ARMATURE PAIRS WHICHARE NORMALLY CLOSED WHEN THEIR WINDINGS ARE DE-ENERGIZED AND CERTAINOTHER CONTACT PAIRS WHICH ARE CLOSED WHEN THEIR WINDINGS ARE ENERGIZED,A PAIR OF POWER CIRCUITS ACROSS SAID POWER INPUT CONDUCTORS AND RUNNINGRESPECTIVELY THROUGH CONTROLLED ELEMENTS OF SAID FIRST AND SECONDTRANSISTORS AND THE CONTROL WINDINGS OF THE FIRST AND SECOND RELAY MEANSRESPECTIVELY ASSOCIATED THEREWITH, SAID FIRST AND SECOND RELAY MEANSEACH INCLUDING A FIRST NORMALLY OPEN CONTACT AND A ARMATURE PAIR FORESTABLISHING A TRANSISTOR ON-SWITCHING CIRCUIT FROM SAID FIRST CAPACITORTO THE POWER INPUT CONNECTIONS OF SAID SECOND AND THIRD RESONANT RELAYSRESPECTIVELY WHEN SAID FIRST AND SECOND RELAY WINDINGS ARE DE-ENERGIZEDAND FOR BREAKING SAID TRANSISTOR ON-SWITCHING CIRCUIT WHEN SAID RELAYWINDINGS ARE ENERGIZED, MEANS FOR NORMALLY BIASING THE CONTROL ELEMENTSOF SAID TRANSISTORS TO OFF SWITCHED STATES, A HOLDING CIRCUIT FOR EACHRELAY MEANS WINDING ESTABLISHED THROUGH A NORMALLY CLOSED CONTACT ANDARMATURE PAIR OF THE OTHER RELAY MEANS AND EACH BEING OPENED UPONENERGIZATION OF THE OTHER RELAY MEANS WINDING, WHEREBY THE HOLDINGCIRCUITS OF SAID RELAY MEANS OPERATE IN FLIP-FLOP MODE, FIRST AND SECONDELECTRICALLY ENERGIZABLE SIGNAL DEVICES, AND FIRST AND SECOND ENERGIZINGCIRCUITS RESPECTIVELY FOR THE FIRST AND SECOND SIGNAL DEVICES RUNNINGFROM ONE POWER CONDUCTOR THROUGH NORMALLY OPEN CONTACT AND ARMATUREPAIRS ON THE FIRST AND SECOND RELAY MEANS TO THE OTHER POWER CONDUCTOR.